Abstract
Since the previous work revealed the higher requirement of riboflavin for White Rock chicks, the requirement of the vitamin for the chicks of the same strain was studied. Two types of riboflavin-deficient basal diets, purified and practical, were supplemented by various levels of riboflavin and fed to day-old chicks for 3 weeks. Typical riboflavin-deficiency symptom, curled-toe paralysis, was observed among the chicks fed with the diets containing riboflavin of about 2.9 mg/kg diet or less. Linear relationship between body weight gain and logarithm of riboflavin level in the diets of both types was observed and the requirement of riboflavin was estimated by the same way mentioned in the previous paper for niacin, which was 6.3 mg/kg with purified diet and 4.0 mg/kg with practical type diet. Although chicks fed with purified diet took about 9% less diet than those fed with practical type diet, the difference in riboflavin requirement between the types of the diet was assumed mostly due to the experimental error among the individual chicks.
